Hi, I just started playing with kdenlive and it really seems to be a good and simple program to use. But now I wonder if it is possible to add an small image into a movie, then I mean pasting a small picture for example an arrow with text pointing to something in the film while the film rolls? I hope you will understand what I mean, English is not my best side

Yes. There are several ways to achieve this.

First, you need to create an "overlay" clip containing the text and arrow. You may use the integrated title editor for simple overlays. Other tools are TheGimp for .png images, and Inkscape for .svg and also .png images. All these tools allow you to keep transparency; this is important, as otherwise your overlay will block all areas of your video clip.

Now, with Kdenlive 15.12 place your video clip on, say, track 2. Place your overlay "clip" on the track immediately above. Make sure that the track containing the overlay clip has its composite mode enabled. That's the rightmost box icon in each track header (leftmost section in timeline).

For more complex compositions, such as using multiple overlays, there is also documentation available.

Thank you for taking your time to answer, it works perfectly